Use ido to checkout branches

(setq magit-completing-read-function 'magit-ido-completing-read)

Extensions

magit-filenotify: refresh status buffer when git tree changes

This module, to be installed with ELPA, comes with a minor mode magit-filenotify which tracks
changes in the source tree using file-notify and refreshes the magit
status buffer. Emacs 24.4 with `file-notify-support' is required for it to
work.